§ 83. Rights in re propria and Rights in re aliena.
Rights may be divided into two kinds, distinguished by the civilians as jura in re propria and jura in re aliena. The latter may also be conveniently termed encumbrances, if we use that term in its widest permissible sense.[[200]] A right in re aliena or encumbrance is one which limits or derogates from some more general right belonging to some other person in respect of the same subject-matter. All others are jura in re propria. It frequently happens that a right vested in one person becomes subject or subordinate to an adverse right vested in another. It no longer possesses its full scope or normal compass, part of it being cut off to make room for the limiting and superior right which thus derogates from it. Thus the right of a landowner may be subject to and limited by that of a tenant to the temporary use of the property; or to the right of a mortgagee to sell or take possession; or to the right of a neighbouring landowner to the use of a way or other easement; or to the right of the vendor of land in respect of restrictive covenants entered into by the purchaser as to the use of it; for example, a covenant not to build upon it.
A right subject to an encumbrance may be conveniently designated as servient, while the encumbrance which derogates from it may be contrasted as dominant. These expressions are derived from, and conform to, Roman usage in the matter of servitudes. The general and subordinate right was spoken of figuratively by the Roman lawyers as being in bondage to the special right which prevailed over and derogated from it. The term servitus, thus derived, came to denote the superior right itself rather than the relation between it and the other; just as obligatio came to denote the right of the creditor, rather than the bond of legal subjection under which the debtor lay.[[201]]
The terms jus in re propria and jus in re aliena were devised by the commentators on the civil law, and are not to be found in the original sources. Their significance is clear. The owner of a chattel has jus in re propria—a right over his own property; the pledgee or other encumbrancer of it has jus in re aliena—a right over the property of some one else.
There is nothing to prevent one encumbrance from being itself subject to another. Thus a tenant may sublet; that is to say, he may grant a lease of his lease, and so confer upon the sub-lessee a jus in re aliena of which the immediate subject-matter is itself merely another right of the same quality. The right of the tenant in such a case is dominant with regard to that of the landowner, but servient with regard to that of the sub-lessee. So the mortgagee of land may grant a mortgage of his mortgage; that is to say, he may create what is called a sub-mortgage. The mortgage will then be a dominant right in respect of the ownership of the land, but a servient right with respect to the sub-mortgage. So the easements appurtenant to land are leased or mortgaged along with it; and therefore, though themselves encumbrances, they are themselves encumbered. Such a series of rights, each limiting and derogating from the one before it, may in theory extend to any length.
A right is not to be classed as encumbered or servient, merely on account of its natural limits and restrictions. Otherwise all rights would fall within this category, since none of them are unlimited in their scope, all being restrained within definite boundaries by the conflicting interests and rights of other persons. All ownership of material things, for example, is limited by the maxim, sic utere tuo ut alienum non laedas. Every man must so restrain himself in the use of his property, as not to infringe upon the property and rights of others. The law confers no property in stones, sufficiently absolute and unlimited to justify their owner in throwing them through his neighbour’s windows. No landowner may by reason of his ownership inflict a nuisance upon the public or upon adjoining proprietors. But in these and all similar cases we are dealing merely with the normal and natural boundaries of the right, not with those exceptional and artificial restrictions which are due to the existence of jura in re aliena vested in other persons. A servient right is not merely a limited right, for all are limited; it is a right so limited that its ordinary boundaries are infringed. It is a right which, owing to the influence of some other and superior right, is prevented from attaining its normal scope and dimensions. Until we have first settled the natural contents and limits of a right, there can be no talk of other rights which qualify and derogate from it.
It is essential to an encumbrance, that it should, in the technical language of our law, run with the right encumbered by it. In other words the dominant and the servient rights are necessarily concurrent. By this it is meant that an encumbrance must follow the encumbered right into the hands of new owners, so that a change of ownership will not free the right from the burden imposed upon it. If this is not so—if the right is transferable free from the burden—there is no true encumbrance. For the burden is then merely personal to him who is subject to it, and does not in truth limit or derogate from the right itself. This right still exists in its full compass, since it can be transferred in its entirety to a new owner. For this reason an agreement to sell land vests an encumbrance or jus in re aliena in the purchaser; but an agreement to sell a chattel does not. The former agreement runs with the property, while the latter is non-concurrent. So the fee simple of land may be encumbered by negative agreements, such as a covenant not to build; for speaking generally, such obligations will run with the land into the hands of successive owners. But positive covenants are merely personal to the covenantor, and derogate in no way from the fee simple vested in him, which he can convey to another free from any such burdens.
Concurrence, however, may exist in different degrees; it may be more or less perfect or absolute. The encumbrance may run with the servient right into the hands of some of the successive owners and not into the hands of others. In particular, encumbrances may be concurrent either in law or merely in equity. In the latter case the concurrence is imperfect or partial, since it does not prevail against the kind of owner known in the language of the law as a purchaser for value without notice of the dominant right. Examples of encumbrances running with then servient rights at law are easements, leases, and legal mortgages. On the other hand an agreement for a lease, an equitable mortgage, a restrictive covenant as to the use of land, and a trust will run with their respective servient rights in equity but not at law.
It must be carefully noted that the distinction between jura in re propria and jura in re aliena is not confined to the sphere of real rights or jura in rem. Personal, no less than real rights may be encumbrances of other rights. Personal, no less than real rights may be themselves encumbered. A debtor, for example, may grant a security over the book debts owing to him in his business or over his shares in a company, as well as over his stock in trade. A life tenancy of money in the public funds is just as possible as a life tenancy of land. There can be a lien over a man’s share in a trust fund, as well as over a chattel belonging to him. The true test of an encumbrance is not whether the encumbrancer has a jus in rem available against all the world, but whether he has a right which will avail against subsequent owners of the encumbered property.
The chief classes of encumbrances are four in number, namely, Leases, Servitudes, Securities, and Trusts. In a later chapter we shall consider these more at length, and in the meantime it is sufficient briefly to indicate their nature.